Motor control.



H. HEYMANN.

MOTOR CONTROL.

APPLICATION FILED M326, 1910.

962,835. Patented June 28, 1910.

Wiwsmssas INS/ENTER L, 252750 EYMANN- 65 Arrow? UNITED STATES PATENT()FFICE.

Figure 1 iH UGO EEYMANN, 0F BERLIN, GERMANY, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NFXV YORK.

MOTOR CONTROL.

iatented J one 28, 1910. Serial No. 546,057.

To all whom it may concern.

Be it known that I, HUGO HEYMANN, a subject of the Emperor of Germany,residing at Berlin, Germany, have invented certain new and usefulImprovements in Motor Cont'rol, of which the following is aspecification.

This invention relates to motor control systems and has for its objectthe provision of means whereby an electric motor may becontrolled-within a wide range in a simple and eflicient manner.

My invention relates more specifically to the control of motors operatedon what is known as the Leonard systel n, wherein the motor is suppliedwith current from a separately excited generator and the speed of themotor is varied by varying the field strength of the generator.

One of the objects of my invention is to provide a greater range ofspeed regulation than is generally given under ordinary operatingconditions. It is often desirable to have in addition to the speedregulation from zero to normal running speed of the motor an increase inthe speed above its normal running speed. It is also desirable that thefield of the 'motor be kept at Full strength until it reaches its normalrunning speed.

In. carrying out my invention I provide, in addition to the regulationof the motor provided through the regulator of the generator field, arheostat for controlling the field of the motor. This rheostat isnormally locked in full field position and is provided with meanswhereby the lever is unlocked so as to permit the field to be Weakenedwhen the motor reaches a predetermined speed.

In the accompanying drawing, in which I have shown my invention embodiedin concrete structure for purposesof illustration, represents adiagrammatic View embodying one form of my invention, afhd Fig. 2 adiagrammatic View of another form of my invention.

Referring first to Fig. 1, 10 represents the armature of a generatorhaving a separately excited field 11. 12 represents the exciter, whichmay be on the same shaft as the generator, as shown. A reversingrheostat 13 is provided by varying the field strength of the generatorand for reversing the same. This field is energized from the conductorsa 1), fed by the exciter 12. hen the arm 14: of the regulator is in theosition shown, the

resistance R is in series with the field of the generator and thisresistance may be varied in the wel -known manner. iVhen' the lever 14-is moved onto the studsof the resistance R, the current through thefield will be re versed.

15 represents the armature of the working motor and 16 the field of thismotor. This field is energized from the exciter 12 and a rheostat orregulator is arranged in series with this field. This regulator consistsof a regulating resistance It provided with a series of studs over whichthe pivoted arm 1'? passes. ()11 the hub of this arm is a segmentalportion provided with a notch 18 adapted to be engaged by the pivotedlever 19. when the arm is in the position in which the resistance. iscut out of the field circuit. it will be engaged by the lever 19 andheld in this position. The opposite end of the lever 19 is operated by acentrifugal governor 20 so arranged that when the motor reaches apredetermined speed, it will shift the lever 19 out of the slot- 18 aiidrelease the arm 17.

In operation, when the motor has reached the highest speed which can beobtained with the-regulation of the field 11 of the generator.

The notch 1s so arranged that or when the motor reaches a predeterminedspeed, the lever turned to insert resistance R in the. field of themotor and thereby increase its speed.

In the form shown in Fig. 2, I have shown substantially the same or'angement, with the exception that the lever 17 is locked by a springpressed lever 21, which normally locks the arm 17 in the full In thiscase the lever 21 is controlled by an electromagnet 22 arranged toattract the lever 21 and release the armature 17, when the motor reachesa predetermined speed. I have shown this electromagnetconnected acrossthe terminals of the motor 23, so that when the countenelectromotiveforce of the motpr reaches a predetermined amount the lever will bereleased. Otherwise the scquenc of operation is the same as in the formshown in Fig. 1.

It will be seen that I have provided a very simple and etlicient meansfor increasing the range of speed of electric motors, and while I havedescribed my invention as embodied in concrete mechanism and asoperating in a specific manner for purposes of illustration, it shouldbe understood that I do not limit my invention thereto, since vari- 17is released and may be 1. The combination. With a separately excitedgenerator supplying eurrent te a motor, of means for varying the'fieldstrength of the generator, a field regulator for the motor and means forpreventing the operation of said regulator until the motor reaches apredetermined speed. '5

2. The combination with a separately cited generator supplying currentto ainotor, of means for varying the field strength the generator, atfield regulator for the meter, and means for preventing the weakening ofthe motor field until the motor reaches a predetermined speed.

3. The combination ,with a separately e1- eited generator supplyingcurrent to a motor, of means for varying the field strength of thegenerator, an auxiliary speed regulator for the motor and means forpreventing the operation of said regulator until the motor reaches apredetermined speed.

4;. The combination with a separately e2;-

l 1 l l cited generator supplying e of means for the generator,

varying the an auxiliary urent to a motor, field strength of sneedregalator for the motor-and eieetromagneticaliy con.-

trolled means for preventing the operation predetermined speed.

5. The combination with a sena cited generator supplying current te an tthe field strength of of means for varying the generator,

an auxiliary speed regal for the motor normally-locked in :tull fieldator position, and means for releasing said regulator when the motorreao mined speed.

6. The combination with hes a predeten a separately excited generatoriplving current to a motor, .1 v n of means for varying the fieldstrength or the generator, an auxiliary speed regulator for the motor.normally located in full hard position, and

In witness my hand this ninth HUGO Witnesses Jellies Hermann, KARLMionnnsen.

electrically controlled means for releasing said regulator when themeter reaches a predetermined speed.

whereoii ha day of ve hereunto set HEYMANK February. 1909.-

